1. Field of the Invention
The present invention relates to an optical device having such a variable optical-characteristic element as a variable focal-length lens, a variable focal-length diffraction optical element, a variable deflection-angle prism, and a variable focal-length mirror, and having an optical system including the variable optical-characteristic element, which are eyeglasses, a video projector, a digital camera, a mobile-phone digital camera, an image pickup device of a PDA (personal digital assistant), an on-vehicle camera, a TV camera, a robot eye, an endoscope, a telescope, a camera finder, and an optical information processor, for example.
2. Description of the Related Art
A lens has been manufactured by polishing glass, and focusing, zooming, and variable power of a camera have been performed by moving a lens group in an optical axial direction via a complicated mechanism using a motor for example.